Consider two relations R(A, B, C) and S(B, D) with R contains 5000 tuples stored in a sequential file sorted on attribute A and S contain 100000 tuples stored in a sequential file sorted on attribute B. Each block can hold 10 R tuples or 10 S tuples. Which one of the following index is most appropriate for answering query R (natural Join) S (Assume index always stored in memory)
